Sport Aviation - August 1998
---BERKUT---
By Ed Kolano
Photos By Alan Staats

Page 2

The side stick has a fore and aft travel of about 4", and 45' side to side. The landing brake is a forward-hinged flat panel which extends from the plane's belly under the rear seater's feet. The brake is extended, via a stickmounted switch, during taxi to help keep pebbles kicked up by the nosewheel out of those intakes. It's also used to add drag in the landing pattern. That's right to add drag. Because the rudders deflect outboard only, the pedals can be independently displaced an estimated 8" when maximum braking is applied. There is no separate toe or heel brake pedal. Brakes are applied by continuing to displace the rudder pedals after full rudder deflection is achieved.

Directional control on the ground is accomplished through differential braking and works well enough to keep the nosewheel within a foot of the taxiway centerline. The brakes are surprisingly effective at maneuvering the airplane through tight turns. Pivot turns are possible, but power must be used to prevent slowing to a halt.

Another nice feature of the Berkut's directional control system is the clear tactile demarcation between full rudder and the beginning of braking. The pilot can easily feel a brake come into play, and does not have to rely on an airplane swerve to let him know. Brake sensitivity is also good, allowing fine modulation without guesswork, and braking effort is fairly light for taxiing tasks with no more than 25 lbs. necessary.

POWER

Takeoff with half fuel and two pilots takes about 15 seconds at a density altitude of 1,600 feet. There is no swerve with full power application, since there's no vertical tail to catch the prop swirl. Rudders become effective for directional control around 40 knots. Pilots of conventional airplanes should remember not to press on both pedals, since both rudders can be deflected simultaneously, adding drag.

A 5 lb. pull unsticks the nosewheel passing 70 knots. While the trim setting determines the stick pull required, this setting allows a light rotation force and easy capture of the takeoff pitch attitude. As the main wheels lift, the slight disharmony between pitch and roll stick forces becomes apparent. The light roll forces and responsive roll result means tiny inadvertent lateral stick displacements while holding back stick can easily occur. Aware of this lateral PIO possibility, it's not difficult to avoid.

Even with the cruise prop, acceleration is brisk. The 200 knot limit on the landing gear allows enough time ,o raise them without concern. There is virtually no pitch change when raising the gear. Three green lights indicate all up.

Averaging a 1,500 fpm climb rate at the best rate of speed of 120 knots, the field of view (FOV) is restricted. The combination of canard and noseup pitch attitude pretty much hide what's in front. A faster cruise-climb should help the FOV. Once level, the FOV improves and the canard doesn't seem as intrusive.

Although the Berkut is a comfortable cruiser, it takes discipline to remain straight and level in this airplane. It'll do it, but the pilot may not want to. Yank it around the sky. Figuratively obliterate clouds and fancied ground targets. Wipe your brow with your imaginary silk scarf, and continue on your way.

There's plenty of power for levelflight acceleration: From 70 kts., the speed doubles in 21 seconds, almost density altitude are 20" manifold pressure, 2,600 rpm with the engine leaned yielding an indicated cruise speed of 190 kts. There is a perceptible high frequency buzz from the engine which can only be felt through the pilot's arms resting on the unpadded sills.